Results will vary depending on your skills.

Please tell us this is some sort of sick and perverse joke; or at least that younger generations aren't this far lost in the throes of a technology-addled era?

3D touch on the iPhone 6 allows you to weigh things directly on your phone, but for some reason, Apple doesn't want people building scale apps. Many have tried, but been rejected by the app store because Apple says "the concept of a scale app is not appropriate for the app store," whatever that means. Asaf Avidan Antonir built a simple game that uses 3D touch to move a dot between lines (think Flappy Bird), but the important part is the "training" function. Within training mode, you can figure out how much force you're exerting to practice moving the dot, or just use the thing as a scale for...whatever you want.